N-gram Insight

To the Editors:

Brian Hayes’s column, “Bit Lit” (May–June), in which he discussed the Google Books project, was fascinating, as usual. I used the Google Books Ngram Viewer to plot the frequency of the total occurrences of Moore’s Law, which predicts that transistor density (and hence computer performance) will double approximately every two years. I searched for “Moore’s Law” and “Moore’s law” in books published from 1965 to 2008. In the period from 1989 to 2002, the Ngram Viewer yielded an exponential trendline described by the equation y = Ae0.3137t where A is a constant and t is the year. The data are an excellent fit to that equation, indicated by an R2 of 0.959. This result says that, in the current database, references per year to Moore’s law doubled about every 2.2 years over that time span, almost keeping up with Moore’s law itself.